JP2530589Y2 - Swivel lock circuit of hydraulic construction machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a swing lock circuit of a construction machine such as a hydraulic shovel.

[0002]

2. Description of the Related Art FIG.
Is common. The direction and flow rate of the pressure oil discharged from the hydraulic pump 1 are controlled by a turning control valve 2, and this pressure oil is guided to the turning motor 3 to rotate the turning motor 3.
The parking motor 3 is used to hold the swivel base when parking or working without performing a swing operation.
Key 4 is attached. The parking brake 4 controls the turning control valve 2, so that a pressure switch 7 operated by a pressure from a shuttle valve 6 installed between oil passages a and b for guiding a signal pressure from a pilot valve 5. Is input, a signal is output from the controller 8, and the solenoid valve 9 is switched to be turned on / off by the pressure of the auxiliary hydraulic power source 10.

A turning lock switch 11 is attached to a signal harness line from the controller 8 to the solenoid valve 9, and when the turning lock switch 11 is turned on / off, a release signal of the parking brake 4 is transmitted. It is turned on and off. That is, the parking brake 4 is released only when the pilot valve 5 is operated while the turning lock switch 11 is off (turning lock is released), the turning control valve 2 is switched, and the turning motor 3 is operated. Is configured. According to this method, when the turning operation is performed while the turning lock switch 11 is on (turning lock),
Since the parking brake 4 is not released, the starting torque of the turning motor 3 is always received by the parking brake 4, and there is a danger that the service life of the parking brake 4 will be shortened.

When the braking torque of the parking brake 4 falls below the starting torque of the turning motor 3 due to wear or damage of the brake, the turning lock switch 11 is turned on (turning lock). Despite this, if you perform a turning operation,
The turning motor 3 rotates, and the upper turning table starts to move, which is very dangerous.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a swing brake lock system for a construction machine such as a hydraulic shovel to reduce the life of a swing parking brake and to improve safety when the parking brake is broken.

[0006]

[MEANS FOR SOLVING THE PROBLEMS] The pressure oil discharged from the hydraulic pump is applied to a parking brake via a turning control valve.
The parking brake 24 is guided to a turning motor provided with a key, and is rotated. The parking brake 24 is provided with an oil passage a, which guides a signal pressure from a pilot valve 25 for controlling the turning control valve 22.
b, a control connected to a pressure switch 29 operated by pressure from a shuttle valve 31 provided between
In a revolving brake device in which the solenoid valve 27 is switched on and off by the pressure of the auxiliary hydraulic power source 26 in response to a signal from the controller 28, the controller 28 is revolved in parallel with the pressure switch 29 with respect to the controller 28. An electromagnetic valve 33 connected to a lock switch 35, connected to a controller 28, and turned on and off by a turning lock switch 35, and connected to an auxiliary hydraulic power source 34 of equal or high pressure for turning operation signal pressure. And a combined shuttle valve 32 is provided between the solenoid valve 33 and the swing control valve 22. The combined shuttle valve 32 connects the swing operation signal oil passages a and b to the input pressure sides 32a and 32c. And the oil passages c and d of the turning control valve 22 are connected to the output pressure side 32.
b and 32d, respectively, and the input pressure side 32e of the combination type shuttle valve 32 is connected to the solenoid valve 33 via an oil passage i. When the swing lock switch 35 is on, the pressure of the auxiliary hydraulic power source 34 is It acts equally on the pilot pressure actuating parts on both sides of the turning control valve 22 via the combination type shuttle valve 32, so that even if the turning operation is performed, the turning control valve 22 is kept neutral so that the turning mode is maintained.
23 was made inoperable.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described with reference to FIG. The hydraulic pump 21 is driven by a motor (not shown).
The turning control valve 22 is a pilot valve 25.
The pressure and the flow rate of the hydraulic oil from the hydraulic pump 21 are controlled by the pressure of the oil passages a and c or b and d for guiding the signal pressure from the hydraulic pump 21, and the rotation direction and speed of the turning motor 23 are controlled. The turning motor 23 is provided with a parking brake 24 which is turned on / off by a pilot signal pressure. The pressure oil from the auxiliary hydraulic pressure source 26 is connected to the parking brake 24 via an oil passage e, a solenoid valve 27 and an oil passage f. The solenoid valve 27 is at the position 27a when the electric signal to the electromagnetic operating part 27c is off, and connects the oil passage f to the tank. When it is on, it is at the position 27b to connect the oil passages e and f.

[0008] The electromagnetic operating portion 27c of the electromagnetic valve 27 is connected to the controller 28 by a signal harness. The pressure switch 29 is connected to the controller 28 and the power supply 30 by a signal harness. The pressure switch 29 is turned on / off by the pressure of the pilot oil passage g from the shuttle valve 31 attached between the oil passages a and b, and is input to the controller as an electric signal. Another combination type shuttle valve 32 includes oil passages a, c and b,
d. The combination-type shuttle valve 32 has a shape in which two shuttle valves 31 are combined, and is for applying the same pressure to the pilot ports on both sides in order to hold the turning control valve 22 neutral. Hereinafter, this is referred to as a combination type shuttle valve. The port 32a of the combination shuttle valve 32 is connected to an oil passage a, the port 32b is connected to an oil passage c, the port 32c is connected to an oil passage b, and the port 32d is connected to an oil passage d. The auxiliary hydraulic pressure source 34 is connected to the port 32e of the combination shuttle valve 32 via the oil passage h, the solenoid valve 33 and the oil passage i. The combination type shuttle valve 32 selects the pressure of the port 32a and the port 32e at a high pressure, and selects the port 32b and the port 32c and the port 32e at a high pressure to generate a pressure at the port 32d.

When the electric signal to the electromagnetic operating section 33a is off, the solenoid valve 33 is at the position 33b, and connects the oil passage i to the tank. When it is on, it is at the position 33c and connects the oil passage i and the oil passage h. The electromagnetic actuating portion 33a of the solenoid valve 33 is provided with a signal heart.
It is connected to the controller 28 by a nest. The turning lock switch 35 is controlled by the signal harness.
The switch 28 is connected to the controller 28 and a power source 30, and inputs ON / OFF of the turning lock switch 35 to the controller 28 as an electric signal. When the pressure switch 29 is turned on, the controller 28 has no time delay and the solenoid valve 27
When the pressure switch 29 is turned off, the electric signal to the electromagnetic operating unit 27c is turned off with a certain time delay. When the turning lock switch 35 is ON (turning lock), an ON electric signal is output to the electromagnetic operating portion 33a of the solenoid valve 33. When the turning lock switch 35 is OFF (turning lock release),
The electric signal to the electromagnetic operation section 33a of the electromagnetic valve 33 is turned off. The turning on / off of the turning lock switch 35 operates without a time delay. At this time, the solenoid valve 27
When the pressure switch 29 is turned on before the turning lock switch 35, the electric signal to the electromagnetic operating portion 27c is turned off with a certain time delay, and the pressure switch 29 is turned on after the turning lock switch 35. When it is turned on, it is kept off.

[0010]

When the operator operates the pilot valve 25, a pressure is generated in the hydraulic pressures a, c or b, d, the swing control valve 22 is switched, and the hydraulic oil from the hydraulic pump 21 is turned by the swing motor. 23, and the turning motor 23 becomes operable. When the turning lock switch 35 is off (turning lock is released); When the pilot valve 25 is operated, the pressure oil generated in the oil passage a or b causes the shutoff valve 3
1. Acts on the pressure switch 29 via the oil passage g. When pressure acts on the pressure switch 29, the pressure switch 29 is turned on. The controller 28 receives the ON signal of the pressure switch 29 and outputs an ON electric signal to the electromagnetic operating portion 27c of the electromagnetic valve 27.
In response to this ON signal, the solenoid valve 27 is switched to the position 27b, and the pressure oil of the auxiliary hydraulic source 26 acts on the parking brake 24 via the oil passage e, the solenoid valve 27 and the oil passage f to release it. This enables the turning motor 23 to operate.

When the turning lock switch 35 is on (turning lock); when the turning lock switch 35 is on (turning lock), an electric signal to the electromagnetic operating portion 33 a of the solenoid valve 33 is turned on. To switch to the position of 33c,
The pressure of the auxiliary hydraulic pressure source 34 is applied to the pilot pressure operating portions 22a and 22b on both sides of the turning control valve 22 via the oil passage h, the solenoid valve 33, the oil passage i, the combined shuttle valve 32 and the oil passages c and d. Works. At this time, when the operator operates the pilot valve 25 to generate pressure in the oil passage a or b, the port 32 of the combination type shuttle valve 32
Pressure acts on a or 32c. However, the auxiliary hydraulic power source 3
4 and the pressure of the hydraulic pressure source 36 of the pilot valve 25 are set to be the same, so that the operator
Despite the operation of 5, the pressure acting on the pilot pressure operating parts 22a, 22b of the turning control valve 22 becomes the same pressure. Since the pilot pressure operating portions 22a and 22b of the turning control valve 22 have a common area on both sides, they do not switch when the same pressure acts.
Since the neutral state is maintained, the turning motor 23 does not operate.

At this time, if pressure is generated in the oil passage a or b, the pressure acts on the pressure switch 29 via the shuttle valve 31 and the oil passage g.
Is turned on, but the electric signal from the controller 28 to the electromagnetic operating portion 27c of the solenoid valve 27 is off, so that the parking brake 2 is turned on.
4 is not released. In other words, in the case of this system, even if the operator performs a turning operation with the turning lock switch 35 turned on (turning lock), no torque is generated in the turning motor 23, so that the load is applied to the parking brake 24. The risk of shortening the service life is eliminated because of the absence of heat. Also parking brake
Even when the performance of the key 24 is significantly reduced due to wear, breakage, etc., the key 24 does not turn and is safe for the operator.

[0013]

With this configuration, when the turning lock switch 35 is on, the same pressure acts on the pilot ports 22a and 22b on both sides of the turning control valve 22, and this operating pressure is applied to the operating pilot valve. 25
, The pressure is equal to or higher than the pressure of the swing motor, so that the neutral state is always maintained, and the turning motor 23 cannot be operated. Therefore, when the turning operation is performed while the turning lock switch is ON as in the prior art, the problem that the parking brake is always received by the starting torque of the turning motor without the parking brake being released and the life thereof is reduced is solved. You.
Also, when the brake torque of the parking brake falls below the starting torque of the swing motor due to wear or breakage of the brake, etc., if the swing operation is performed while the swing lock switch is on, the swing motor rotates and the upper swing is performed. The problem of the platform starting to move has been completely resolved.

[Brief description of the drawings]

FIG. 1 is a known swing lock circuit diagram.

FIG. 2 is a swing lock circuit diagram according to the present invention.

[Explanation of symbols]

a to i Oil passage 1 Hydraulic pump 2 Swivel control valve 3 Swivel motor 4 Parking brake 5 Pilot valve 6 Shuttle valve 7 Pressure switch 8 Controller 9 Solenoid valve 10 Auxiliary hydraulic source 11 Swivel lock switch 21 Hydraulic pump 22 Swivel control valve 22a, 22b Pilot pressure operating part 23 Swing motor 24 Parking brake 25 Pilot valve 26 Auxiliary hydraulic power source 27 Solenoid valve 27c Electromagnetic operating part 28 Controller 29 Pressure switch 30 Power supply 31 Shuttle valve 32 Combined shuttle valve 32a to 32e Port 33 Solenoid valve 34 Hydraulic source for auxiliary 35 Swivel lock switch 36 Hydraulic source

Claims (1)

(57) [Scope of request for utility model registration] 1. A hydraulic brake pump comprising: a hydraulic pump having a parking brake for guiding hydraulic oil discharged from a hydraulic pump through a turning control valve to a rotating motor having a parking brake; Connected to a pressure switch (29) operated by pressure from a shuttle valve (31) provided between oil passages a and b for guiding a signal pressure from a pilot valve (25) for controlling a control valve (22). The turning brake device in which the solenoid valve (27) is switched on and off by the pressure of the auxiliary hydraulic pressure source (26) in response to the signal from the controller (28) provided by the controller (28). ), A turning lock switch (35) is connected in parallel with the pressure switch (29),
In addition, a turning lock switch (35) is added to the controller (28).
The solenoid valve (33) connected to the auxiliary hydraulic pressure source (34) of the swing operation signal pressure and the equal pressure or the high pressure is connected by turning on and off the solenoid valve (33) and the swing control valve. (22), a combined shuttle valve (32) is provided, and the combined shuttle valve (32) connects the turning operation signal oil passages (a, b) to the input pressure side.
(32a, 32c) and control valve for turning (22)
Oil passages (c, d) are connected to the output pressure side (32b, 32d), respectively.
The input pressure side (32e) of the combination shuttle valve (32) is connected to the solenoid valve (33) via an oil passage (i), and when the swing lock switch (35) is on, an auxiliary hydraulic pressure source (34) Pressure acts equally on the pilot pressure actuating parts on both sides of the turning control valve (22) through the combined shuttle valve (32), so that the turning control valve (22) does not A turning lock circuit for a hydraulic construction machine, characterized in that the turning motor (23) cannot be operated by maintaining neutral.